Microbial processes in bee colonies 1
2 Topics in this presentation Bee colony = microbial system Acidity Oxygen Ferro-Bee (iron and iron management)
What happens inside the hive 3
Microbial and anaerobic processes 4 Beekeeping practice Problems with the bee colonies
Bee system = microbial system 5 Bees are visible, microorganisms are not visible Microorganisms determine what happens with the bees and their behaviour Bacteria Viruses Bacteria magnification 400x Viruses magnification 20.000 x
6 Where are the microorganisms Inside the bees On the bees In the food Inside the hive
Where are the microorganisms 7 Inside and on the bees: Gut (3 parts) Fat body (mycetocytes) Other cells in the bee body Skin (cuticula), mouth parts Possibly also in the brain part
Entries in the bee body for the microorganisms
Figure 1: Composition and spatial organization of bacterial communities in the honey bee gut. From Gut microbial communities of social bees Waldan K. Kwong & Nancy A. Moran Nature Reviews Microbiology 14, 374 384 (2016) doi:10.1038/nrmicro.2016.43 9
10 Where are the microorganisms Outside the bees: Nectar Honey Bee bread Bee hive Flowers
Processes in the bee colony 11
12 Important processes Production of energy Production of acids Defense against varroa and diseases, such as viruses
13 Production of energy Forming of biochemical energy from sugar Used for flying and movement
14 Acidity in the hive By acid producing bacteria: Acetic acid bacteria Lactic acid bacteria Fungi, e.g. Penicillium Optimal acidity level: ph 4,5 6,0
15 Production of acids Acetic acid bacteria: Glucose (fermentation) ethanol acetic acid Lactic acid bacteria: Glucose lactic acid Fungi: Glucose gluconic acid
Undesired processes which can 16 take place No sufficient acidity (ph > 7) 1. acid production < consumption/breakdown Too much acidity (ph < 4) 1. too many acids 2. too many strong acids
Acid dissociation constants pka of several common organic acids 17 Acetic acid 4,76 weak acid Succinic acid 4,20 Gluconic acid 3,86 Lactic acid 3,86 Formic acid 3,77 Citric acid 3,13 Fumaric acid 3,03 Oxalic acid 1,25 strong acid
How a lack of acidity occurs 18 By unsufficient production of acids (e.g. no acetic acid bacteria) By evaporation of acids, at high temperatures By consumption, e.g. by Bacillus bacteria During breakdown of proteins liberation of ammonia
Consequences of lack of acidity 19 Abundant bacterial growth and growth of different bacteria, e.g. Serratia bacteria in haemolymphe Formation of biofilms, consequence: obstruction of trachaea Examples of biofilm: tooth placque, stomach ulcer
Biofilms 20 A biofilm contains several types of bacteria A biofilm maintains its own internal environment Inside a biofilm there is an anaerobic situation Biofilms are hardly accessible, e.g. for antibiotics
Significance of lack of acidity for the 21 beekeeping practice (ph >7) Increased risks, e.g. varroa Ocurrence of mineral deficiencies diseases Bacterial growth production of signaling agents (neurotransmitters = nerval and muscular stimulants) Growth of different bacteria agitation (aggression)
Too much acidity (ph < 4) 22 Lactic acid is produced by lactic acid bacteria, this happens always by bacteria which are already present Production of lactic acid can be increased strongly, e.g. by manganese (Mn 2+ ) By application of formic acid or oxalic acid lactic acid production is also stimulated
Oxygen 23
Situations without oxygen 24 Situations with low or no oxygen occur frequently The bees go to the oxygen after opening the hive Bearding, during warm weather or overfull hives
Where arise situations without oxygen 25 In the bee hive, at high bee densities Between the frames, by insufficient circulation Inside the closed brood cells Inside the bee bread Inside the bees, by trachaeal closures
How situations without oxygen arise 26 Too low oxygen level by high consumption/metabolism Too much CO 2 (by the many bees, by fermentation) During high temperatures (summer) By unsufficient movements (lazy bees) By blocking oxygen supply (trachaea, bee bread, brood cells)
Consequences of lack of oxygen 27 90% decrease in energy production within 5 minutes Liberation of minerals Growth of different bacteria Diseases, by bacteria, by viruses
Lower energy production 28
Liberation of minerals 29 Iron in the form of Fe 2+ Manganese in the form of Mn 2+ Zinc in the form of Zn 2+
Bacteria and oxygen 30 Aerobic bacteria ( + oxygen) Anaerobic bacteria ( - oxygen) Facultative anaerobic bacteria ( + or - oxygen) Oxygen determines which bacteria grow Wenn lack of oxygen occurs a sudden reversal takes place from aerobic(+) bacteria to anaerobic(-) bacteria
Examples of bacteria 31 Bacteria on the skin ( + oxygen ) Bacteria on vegetables, fruits, plants ( + oxygen ) Lactic acid bacteria in bee bread ( - oxygen ) American foul brood bacteria ( - oxygen ) Serratia, Staphylococcus ( + or oxygen )
Meaning of anaerobic conditions in 32 beekeeping practice Lazy, slow moving bees Increased production of neurotransmitters Different behaviour, e.g. agitation, aggression Swarming behaviour Bees move to the edges for additional oxygen Bees leave the hive
What happens in bee bread 33 Bee bread = nectar + pollen At first: growth of ordinary bacteria (+ oxygen) These block oxygen supply * ( biofilm ) anaerobic situation Secondly: growth of lactic acid bacteria (- oxygen) Minerals are liberated from pollen (e.g. Fe 2+, Mn 2+, Zn 2+ ) * During wine manufacturing yeasts grow first, these produce a lot of CO 2 ; secondly oxygen is displaced. Then different microorganisms will grow.
Pollen digestion 34 Pollen grain Holes, due to digestion Lactic acid bacteria
Measures against lack of oxygen 35 Good ventilation inside the hive (placement of hives has influence, e.g. in relation to wind) Active bees (adequate feeding) = Ferro-Bee Splitting colonies not too late (hives not too crowdy) Do not place bee hives in the full sun Avoid placement of hives in a humid environment
Iron and iron management 36
Feeding additional iron, Ferro-Bee 37 Concept, based on an idea (2011) Globally the most frequent mineral deficiency Low bee losses in Australië (pollen of Eucalyptus punctata has a very high iron content) Development of concept (2012 2016)
Iron 38 Difficult, because bad solubility Soluble in acid circumstances, ph < 7.0 Unsoluble at ph > 7.0 Formation of insoluble aggregates removal, not biologically available any more
39 Iron in bees A bee contains 0,02 0,05 mg of iron A bee colony contains about 1 gram of iron A bee colony collects 12 20 grams of iron per year Present in fat body, bound to proteins Fat body = storage of iron (liver function) Present in other parts of the body, e.g. in magnetic particles (for navigation purposes)
40 Iron management in bee colonies Supply in excess Constant supply, constant removal A bee colony withstands a lot of iron A bee colony adapts in a short term
Iron management in bee colonies 41 Iron is present everywhere (bees, honey, wax, propolis) Enough iron present, not always available Iron not available after conversion of Fe 2+ in Fe 3+ Only Fe 2+ is biologically relevant Iron as Fe 3+ : in rust in red soils
Wenn iron deficiency can occur 42 In anaerobic conditions At higher ph levels, precipitation in unsoluble forms Too much manganese in pollen (e.g. in heather) Sites in swampy areas and peatlands
Philosophy behind Ferro-Bee 43 Iron is always problematic Competition on iron in the system Insight in varroa-problem Targeted feeding with
Other reasons for iron supply 44 Administering something the bees need More active bees Better ratio between iron and manganese No forming of manganese containing toxins Suppression of reproduction at the end of season Name Chemical abbreviation Atomic number Molecular Weight Values Iron Fe 26 56 2+, 3+ Manganese Mn 25 55 2+, 3+, 4+, 5+, 7+
Wenn to apply Ferro-Bee? 45 Regularly, 1x per 2 3 weeks During humid conditions In the winter feeding Not compatible with anti-varroa treatments, such as formic acid, oxalic acid and thymol User instructions: https://ferrobee.com/product/ferro-bee/
Thank you for your attention 46
Contact 47 Science in Water B.V. / Ferro-Bee Maarten van Hoorn Blomswaard 35 1391 VB Abcoude Netherlands Tel. +31 294 285165 Cell: + 31 6 3606 2236 Mail: info@science-in-water.com Mail: info@ferrobee.com Website: www.science-in-water.com Website: www.ferrobee.com